A copy and paste job. Evidence for evolution.

• Genetics. The first modern synthesis was the successful integration of Gregor Mendel's work on heritability with Darwin's ideas. There still wasn't a physical mechanism, but we at least knew how genetics worked at a high level. Other early work in genetics addressed many of the finer points and nuances of the relationship between inheritance, genetic variability, and selection, providing mathematical formula that describe evolutionary changes at a individual or population level.
• Biochemistry and molecular biology. The physical basis of traits, heritability, and genetic variability was found later, with the discovery of DNA and its role in the process of life and reproduction. As more work was done on this front, we were able to give an increasingly detailed picture of evolution at a molecular level, including the source of genetic variability via mutations/errors in DNA and the relation between phenotypic and genetic traits.

The other main aspect of the modern evolutionary biology is the reconciliation of the theory of evolution with the huge amounts of diverse data that other fields had produced, as well as the integration of new supporting evidence.

• Paleontology. Fossilized remains showed significant changes through time, and there was a legitimate concern that the gradual process of natural selection could account for these changes. The original distinction between micro- and macro-evolution was made by scientists, but eventually discarded as further investigation and experimentation into mutation rates and selection pressures showed that that such a distinction was unnecessary.
• Embryology and developmental biology. The similarity in the development of embryos among very different species was originally a mystery. Evolution proposed common descent as an explanation, and understanding the molecular basis for evolution shed significant light on the developmental process and its evolution.
• Taxonomy and phylogeny. Humans have always attempted to classify and categorize the world around them, and life was not exempt from this. Existing systems of classification were obviously not based on shared evolutionary history, resulting in discrepencies among themselves and with new systems inspired by evolutionary theory that had to be resolved. In the process, the important field of phylogeny was developed to better understand the family tree of all life.

As science progressed, newer developments expanded the original modern synthesis. Some interesting recent ones are:

• Epigenetics. It turns out that environmental effects on an organism's genome can sometimes induce changes that persist in future generations. In other words,
• Higher-order evolution. Initially, we had only considered that the phenotypic traits were under selection and as a result have focused on inferring the parameters of this process. But we have become increasingly aware that these parameters themselves can experience selective pressures. That is, the ability to evolve is itself a trait that undergoes adaptation.
• Neutral theory. This theory suggests that much of the genetic diversity of life is not generated directly by selective pressures, but through the accumulation and persistence of "neutral" changes that don't affect the survivability of the organisms.